JP6353320B2 - Method for producing composite molded body - Google Patents

Description

  The present invention relates to a method for producing a composite molded body including a metal molded body using a thermal spraying method.

As a method for forming a film layer made of another material on the surface of a metal molded body, a thermal spraying method is employed.
Moreover, sandblasting is widely used as a pretreatment of a metal molded body for forming a coating layer by a thermal spraying method (Patent Documents 1 to 3).

Japanese Patent Application Laid-Open No. 11-106881 JP 2005-314732 A JP 2010-284192 A

  An object of the present invention is to provide a method for producing a composite molded body, which can obtain a composite molded body having an increased bond strength between a metal molded body and a coating layer formed by a thermal spraying method.

The present invention
A method for producing a composite molded body having a coating layer on the surface of a metal molded body serving as a substrate,
The coating layer is made of a different constituent material or the same constituent material from the metal molded body as the base material,
A step of continuously irradiating the metal formed body surface with laser light at an irradiation speed of 2000 mm / sec or more using a continuous wave laser;
Provided is a method for producing a composite molded body, which includes a step of forming a coating layer by a thermal spraying method on the surface of the metal molded body irradiated with laser light in the previous step.

  According to the production method of the present invention, it is possible to obtain a composite molded body in which a metal molded body serving as a base material and a coating layer are bonded with high bonding strength.

(A) is a side view of the composite molded object obtained with the manufacturing method of this invention, (b) is a perspective view of the metal molded object used with the composite molded object of (a). (A) is a side view of the composite molded body (another embodiment) obtained by the manufacturing method of the present invention, and (b) is a perspective view of a metal molded body used in the composite molded body of (a). Explanatory drawing of the continuous wave laser irradiation process in the manufacturing method of this invention. Explanatory drawing of the continuous wave laser irradiation process (another embodiment) in the manufacturing method of this invention. Explanatory drawing of the continuous wave laser irradiation process (further embodiment) in the manufacturing method of this invention. Explanatory drawing of the continuous irradiation pattern of a laser beam. (A) is sectional drawing when it sees from the arrow direction between DD shown in FIG. 6, (b) is sectional drawing of another embodiment when it sees from the arrow direction between DD shown in FIG. (A) is a cross-sectional view when viewed from the direction of the arrow between AA shown in FIG. 6, (b) is a cross-sectional view when viewed from the direction of the arrow between BB shown in FIG. 6, (c) Sectional drawing when it sees from the arrow direction between CC shown in FIG. The perspective view of the metal molded object which is a base material used in the Example. (A), (b) is a figure which shows the manufacturing method of the composite molded object of an Example, (c), (d) is explanatory drawing of the measuring method of the joint strength between a base material and a film | membrane layer.

As shown in FIG. 1 (a) or FIG. 2 (a), the composite molded body 1 obtained by the production method of the present invention has a metal molded body 10 and a coating layer 20 that are base materials integrated with high bonding strength. It is a thing.
The metal molded body 10 as a base material is made of a known metal depending on the application. For example, iron, various stainless steels, aluminum, zinc, titanium, copper, magnesium, tungsten and alloys containing them, tungsten carbide, The thing chosen from cermets, such as chromium carbide, can be mentioned. Further, the present invention can be applied to a metal obtained by subjecting the above metal to a surface treatment such as alumite treatment or plating treatment.
The coating layer 20 is made of a constituent material selected from metals, ceramics, cermets, and resins.

The process of continuously irradiating the surface of the metal molded body 10 as a base material with laser light at an irradiation speed of 2000 mm / sec or more using a continuous wave laser will be described.
As shown in FIG. 1 (b) or FIG. 2 (b), an irradiation speed of 2000 mm / sec or more using a continuous wave laser on the surface (film layer forming surface) 12 of the metal molded body 10 as a base material. Irradiate laser light continuously.
In this step, the coating layer forming surface 12 can be roughened in a very short time by continuously irradiating the coating layer forming surface 12 with laser light at a high irradiation rate.
The film layer forming surface 12 of the metal molded body 10 may be a flat surface as shown in FIG. 1B, a curved surface, a surface having both a flat surface and a curved surface, or an uneven surface. It may be on the surface.
The metal molded body 10 in FIG. 1B irradiates the film forming surface 12 so that a large number of straight lines 12a parallel to the length direction are formed.
The metal molded body of FIG. 2B has a plurality of straight lines (laser irradiation) parallel to the length direction over planes having different heights including the stepped portion, with the film forming surface 12 including the concave portion 11. Irradiation is performed so that 12a is formed.

The irradiation speed of the continuous wave laser is preferably 2000 to 20,000 mm / sec, more preferably 2,000 to 18,000 mm / sec, and further preferably 2,000 to 15,000 mm / sec.
When the irradiation speed of the continuous wave laser is within the above range, the processing speed can be increased (that is, the processing time can be shortened), and the bonding strength between the metal molded body 10 and the coating layer is maintained at a high level. be able to.

In this step, it is preferable that the laser beam is continuously irradiated so that the processing time when the following requirements (A) and (B) are satisfied is in the range of 0.1 to 30 seconds.
(A) The irradiation speed of laser light is 2000-15000 mm / sec.
(B) The area of the coating layer forming surface of the metal molded body is 100 mm ²
When the processing time for requirements (A) and (B) is within the above range, the entire surface of the coating layer forming surface 12 can be roughened.

For example, the following method can be applied to the continuous irradiation of the laser beam, but there is no particular limitation as long as the method can roughen the coating layer forming surface 12.
(I) As shown in FIGS. 3 and 4, a straight line or a curve is formed from one side (short side or long side) side to the opposite side side of the film layer forming surface (for example, rectangular) 12. The method of forming a plurality of straight lines or curves by repeatedly irradiating as described above.
(II) Continuous irradiation so that a straight line or a curve is continuously formed from one side of the coating layer forming surface 12 to the opposite side, and this time, a straight line or a curve is formed at intervals in the opposite direction. To repeat the continuous irradiation as described.
(III) A method in which continuous irradiation is performed from one side of the coating layer forming surface 12 to the opposite side, and this time continuous irradiation is performed in the orthogonal direction.
(IV) A method of continuously irradiating the film layer forming surface 12 at random.

When carrying out the methods (I) to (IV), it is also possible to form a single straight line or a single curve by continuously irradiating a laser beam a plurality of times.
Under the same continuous irradiation conditions, the degree of roughening of the coating layer forming surface 12 increases as the number of times of irradiation (number of repetitions) for forming one straight line or one curve increases.

In the methods (I) and (II), when forming a plurality of straight lines or a plurality of curves, each straight line or curve is equally spaced within a range of 0.005 to 1 mm (b1 interval shown in FIG. 3). The laser beam can be continuously irradiated so as to be formed.
The interval at this time is made larger than the beam diameter (spot diameter) of the laser beam, and the number of straight lines or curves at this time depends on the area of the coating layer forming surface 12 of the metal molded body 10. Can be adjusted.

In the methods (I) and (II), when a plurality of straight lines or a plurality of curves are formed, the respective straight lines or curves are in the range of 0.005 to 1 mm (b1 interval shown in FIGS. 3 and 4). The laser beam can be continuously irradiated so as to be formed at equal intervals.
These plural straight lines or plural curves can be made into one group, and a plurality of groups can be formed.
At this time, the intervals between the groups can be equal to each other within a range of 0.01 to 1 mm (interval b2 shown in FIG. 4).
Instead of the continuous irradiation method shown in FIGS. 3 and 4, as shown in FIG. 5, a continuous irradiation method without interruption is also possible from the start of continuous irradiation to the end of continuous irradiation.

The continuous irradiation of the laser beam can be performed, for example, under the following conditions.
The output is preferably 4 to 4000 W, more preferably 50 to 2500 W, further preferably 100 to 2000 W, and further preferably 250 to 2000 W.
The beam diameter (spot diameter) is preferably 5 to 200 μm, more preferably 5 to 100 μm, further preferably 10 to 100 μm, and further preferably 11 to 80 μm.
Furthermore, the preferable range of the combination of the output and the spot diameter can be selected from the energy density (W / μm ² ) obtained from the laser output and the laser irradiation spot area (π × [spot diameter / 2] ² ).
Energy density (W / μm ²⁾ is preferably from 0.1 W / [mu] m ² or more, more preferably 0.2~10W / μm ^2, more preferably 0.2~6.0W / μm ^2.
When the energy density (W / μm ² ) is the same, the larger the output (W), the larger the spot area (μm ² ) can be irradiated with laser, so the processing speed (laser irradiation area per ^second ) ; Mm ² / sec) is increased, and the processing time can be shortened.
The wavelength is preferably from 300 to 1200 nm, more preferably from 500 to 1200 nm.
The focal position is preferably −10 to +10 mm, more preferably −6 to +6 mm.

A preferable relationship among the irradiation speed of the continuous wave laser, the laser output, the laser beam diameter (spot diameter) and the energy density is that the irradiation speed of the continuous wave laser is 2,000 to 15,000 mm / sec, and the laser output is 250 to 2000 W, the laser beam diameter (spot diameter) of 10 to 100 [mu] m, the energy density obtained from the laser output and the spot area ([pi × [spot diameter / 2] ²⁾ (W / [mu] m ²⁾ is 0.2~10W / Μm ² range.

  A known continuous wave laser can be used, for example, YVO4 laser, fiber laser (preferably single mode fiber laser), excimer laser, carbon dioxide laser, ultraviolet laser, YAG laser, semiconductor laser, glass laser, ruby. Lasers, He—Ne lasers, nitrogen lasers, chelate lasers, and dye lasers can be used. Among these, since the energy density is increased, a fiber laser is preferable, and a single mode fiber laser is particularly preferable.

In the method for producing a composite molded body of the present invention, the continuous layer laser is used to continuously irradiate the film layer forming surface 12 of the metal molded body 10 with laser light at an irradiation speed of 2000 mm / sec or more. The portion irradiated with the laser beam continuously is roughened.
One embodiment of the state of the coating layer forming surface 12 of the metal molded body 10 at this time will be described with reference to FIGS.
In addition, if the surface is roughened using a continuous wave laser, it can be used for a metal molded body or part thereof having a shape or hardness (for example, tungsten) that cannot be sufficiently roughened by sandblasting. Is also unnecessary.

As shown in FIG. 6, laser light (for example, a spot diameter of 11 μm) is continuously irradiated to form a large number of lines (in the drawing, three lines 61 to 63 are shown. The interval between the lines is about 50 μm). Can be roughened. The number of times of irradiation on one straight line is preferably 1 to 10 times.
At this time, the surface layer part of the metal molded body 10 including the roughened film layer forming surface 12 is as shown in FIGS. 7A and 8A to 8C. The “surface layer portion of the metal molded body 10” is a portion from the surface of the metal molded body 10 to the depth of an open hole (stem hole or branch hole) formed by roughening. The depth ranges from about 50 to 500 μm.
In addition, when the frequency | count of irradiation to one straight line exceeds 10 times, the level of roughening can be raised more and the joint strength of the metal molded body 10 and the film layer 20 in the composite molded body 1 can be increased. Can be increased, but the total irradiation time becomes longer. For this reason, it is preferable to determine the number of times of irradiation to one straight line in consideration of the relationship between the desired bonding strength and the manufacturing time. When the number of times of irradiation to one straight line is more than 10 times, it is preferably more than 10 times to 50 times or less, more preferably 15 to 40 times, further preferably 20 to 35 times.

As shown in FIGS. 7 and 8, the surface layer portion of the metal molded body 10 including the roughened coating layer forming surface 12 has an open hole 30 having an opening 31 on the coating layer forming surface 12 side. Yes.
The opening hole 30 includes a trunk hole 32 having an opening 31 formed in the thickness direction, and a branch hole 33 formed in a direction different from the trunk hole 32 from the inner wall surface of the trunk hole 32. One or a plurality of branch holes 33 may be formed.
As long as the bonding strength between the metal molded body 10 and the coating layer 20 can be maintained in the composite molded body 1, a part of the open holes 30 may be composed only of the trunk holes 32 and may not have the branch holes 33.

As shown in FIGS. 7 and 8, the surface layer portion of the metal molded body 10 including the roughened coating layer forming surface 12 has an internal space 40 having no opening on the coating layer forming surface 12 side. .
The internal space 40 is connected to the open hole 30 by a tunnel connection path 50.

As shown in FIG. 7B, the surface layer portion of the metal formed body 10 including the roughened film layer forming surface 12 has an open space 45 in which a plurality of open holes 30 are combined. Alternatively, the open space 45 may be formed by combining the open hole 30 and the internal space 40. One open space 45 has a larger internal volume than one open hole 30.
In addition, the many open holes 30 may be united and the groove-shaped open space 45 may be formed.

  Although not shown, two internal spaces 40 as shown in FIG. 8A may be connected by a tunnel connection path 50, or an open space 45 and an opening as shown in FIG. The hole 30, the internal space 40, and another open space 45 may be connected by a tunnel connection path 50.

  The internal space 40 is all connected to one or both of the open hole 30 and the open space 45 through the tunnel connection path 50. In the composite formed body 1, the bonding strength between the metal formed body 10 and the coating layer 20 is high. If it can be maintained, a part of the internal space 40 may be a closed space that is not connected to the open hole 30 and the open space 45.

The details of the formation of the open hole 30 and the internal space 40 as shown in FIGS. 7 and 8 when the laser beam is continuously irradiated are unknown, but the laser beam is continuously irradiated at a predetermined speed or more. When a hole or a groove is once formed in the film layer forming surface 12 of the metal molded body 10, the molten metal rises and covers or dams, resulting in the opening hole 30, the internal space 40, and the opening. It is considered that the space 45 is formed.
Similarly, the details of the formation of the branch hole 33 and the tunnel connection path 50 of the open hole 30 are also unknown, but the side wall portion of the hole or groove is caused by the heat accumulated near the bottom of the hole or groove once formed. As a result of melting, the inner wall surface of the trunk hole 32 is melted to form the branch hole 33, and the branch hole 33 is further extended to form the tunnel connection path 50.
When a pulse laser is used instead of a continuous wave laser, open holes and grooves are formed in the coating layer forming surface 12 of the metal molded body 10, but as shown in FIGS. An internal space that does not have an opening and a connection passage that connects the open hole and the internal space are not formed.

  The process of irradiating the surface of the metal molded body 10 that is a base material with a continuous wave laser is applied to an untreated metal molded body, but if necessary, other roughening such as sand blasting or etching is performed. After the treatment by the surface method, a continuous wave laser can be further irradiated.

  In the next step, the coating layer 20 is formed on the coating formation surface 12 of the metal molded body 10 irradiated with the laser beam. A thermal spraying method is used as a method of forming the coating layer 20.

The thermal spraying method can be appropriately selected from known thermal spraying methods according to the constituent material of the coating layer 20.
As the thermal spraying method, flame spraying using combustion gas, high-speed flame spraying, explosion irradiation, arc spraying using electricity, plasma spraying, RF plasma spraying, electromagnetic acceleration plasma spraying, line explosion spraying, electric thermal explosion powder spraying method, Laser spraying using laser light, other laser / plasma spraying, cold spraying, etc. can be applied.

The constituent material of the coating layer 20 is selected from metals, ceramics, cermets, and resins, and can be sprayed.
Examples of metals include copper, brass, phosphor bronze, aluminum bronze, tin, molybdenum, tungsten, nickel, nickel-aluminum, nickel-chromium, carbon steel, steel, stainless steel, and alloys containing these (including self-fluxing alloys). Known materials can be used.
The metal used as the constituent material of the coating layer 20 may be the same as the metal of the metal molded body serving as the base material.

  Ceramics include zirconia, alumina, gray alumina, alumina-titania, titania, chromia, alumina-zirconium, mullite, spinel, magnesia-silica, RC (chromia-silica-alumina), RA (alumina-silica), RZS (zirconia). -Silica), known materials such as RZ (zirconia-calcium carbide) can be used.

  The cermet is made of an inorganic compound such as a metal oxide, carbide or boride and a metal as a binder, and tungsten carbide, chromium carbide or the like can be used.

  The resin is not particularly limited as long as the spraying method can be applied, and is a polyamide-based resin (aliphatic polyamide such as PA6 or PA66, aromatic polyamide), a copolymer containing styrene units such as polystyrene, ABS resin, AS resin, Polyethylene, copolymers containing ethylene units, polypropylene, copolymers containing propylene units, other polyolefins, polyvinyl chloride, polyvinylidene chloride, polycarbonate resins, acrylic resins, methacrylic resins, polyester resins, polyacetals Examples thereof include thermoplastic resins such as resins, polyphenylene sulfide resins, polyether ether ketone (PEEK), and polyether ketone (PEK).

When the constituent material of the coating layer 20 is sprayed on the coating layer forming surface 12 of the metal molded body 10, the remaining surface excluding the coating layer forming surface 12 is sprayed in a masked state.
When the thermal spraying method is applied in this way, the constituent material penetrates into the open hole 30, the internal space 40, the open space 45, and the tunnel connection path 50 formed in the surface layer portion of the coating layer forming surface 12. The film layer 20 is formed by laminating.
For this reason, the metal molded body 10 and the coating layer 20 of the composite molded body 1 are bonded with higher bonding strength than when the sandblast treatment is performed as in the prior art.

Examples 1-4, Comparative Examples 1-4
<Laser irradiation process: FIG. 10A>
A continuous wave laser is irradiated on the film forming surface 12 (6 mm × 20 mm) near the center of one surface of the metal molded body 10 (30 mm × 30 mm × 3 mm; see FIG. 9) as a base material under the conditions shown in Table 1. (Irradiation mark 12a) to make a rough surface having a porous structure.
However, Comparative Examples 1 to 4 do not carry out the laser irradiation step shown in FIG.

<Spraying process: FIG. 10B>
Next, the coating layer 20 (thickness 20 μm) was formed on the coating formation surface 12 irradiated with the continuous wave laser by the thermal spraying method shown in Table 2. The thermal spraying was performed while blowing cold air and adjusting the irradiation time so that the surface temperature of the laser irradiation surface of the base metal did not exceed 150 ° C.
In both the examples and comparative examples, the composite molded body 1 in which the coating layer 20 was formed on the base material 10 was obtained.

Next, as shown in FIG. 10 (c), the film layers 20 of the two composite molded bodies 1 were bonded to each other with the adhesive layer 25 in a state of facing each other.
Next, as shown in FIG. 10D, the bonding strength and the bonding strength when pulled in the opposite direction were measured, and the final fractured state was observed.
The results are shown in Table 2.

  In Examples 1 to 4, the base material and the coating layer were integrated with high bond strength.

Experimental Example As shown in Table 3, the processing time when a continuous wave laser and a pulse laser were used was evaluated for the same processing area of the metal molded body.

As can be confirmed from the comparison of the processing times of Experimental Example 1 and Comparative Experimental Example 1, and Experimental Example 2 and Comparative Experimental Example 2, when the continuous wave laser was used, the processing time could be greatly shortened. This difference in processing time becomes a very large difference in productivity when mass-producing on an industrial scale.
Although the technology of roughening the metal surface using a pulse laser is known, when the technology is applied as a pretreatment for the thermal spraying method, it is greatly inferior in terms of productivity compared to the present invention, Further, as described in the description of FIGS. 7 and 8, when a pulse laser is used, the porous structure as shown in FIGS. 7A and 8 cannot be obtained.

The production method of the present invention can provide a composite molded body including a metal molded body serving as a base material and a metal molded body in which a coating layer is bonded with high bonding strength.
The composite molded body obtained by the production method of the present invention can be obtained by selecting and combining the metal molded body as a base material and the constituent material of the coating layer, for example, various screws, various shafts, various blades, rollers, press dies. , Rotary kilns, stirring blades, stirring blades, cyclones, engine parts, electrical parts, machine parts, furniture, etc.

DESCRIPTION OF SYMBOLS 1 Composite molded object 10 Base material 12 Film layer formation surface 20 Film layer

Claims (3)

A method for producing a composite molded body having a coating layer on the surface of a metal molded body serving as a substrate,
The coating layer is made of a different constituent material or the same constituent material from the metal molded body as the base material,
A step of continuously irradiating the metal formed body surface with laser light at an irradiation speed of 2000 mm / sec or more using a continuous wave laser;
The manufacturing method of a composite molded object which has the process of forming a film layer by the thermal spraying method on the said metal molded object surface irradiated with the laser beam in the front process. The metal molded body as the base material is selected from iron, iron alloy, stainless steel, aluminum, aluminum alloy, zinc, zinc alloy, titanium, titanium alloy, copper, copper alloy, magnesium, magnesium alloy, tungsten and tungsten alloy The manufacturing method of the composite molded object of Claim 1 which is.   The manufacturing method of the composite molded object of Claim 1 or 2 whose constituent material used as the said film | membrane layer is chosen from a metal, ceramics, a cermet, and resin.

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